1. Field of the Invention
The present invention relates to a magnet wire suitable for use in hermetically sealed electric motors, commonly referred to as hermetic motors. Such motors are disclosed, for example, in Hannibal et al U.S. Pat. Nos. 3,445,059; Rundell 3,544,240; Randall 3,518,031; and Rundell 3,610,784. The term "magnet wire", in its broadest sense, refers to an insulated metal (preferably copper or aluminum) wire used in coils of electromagnetic machines, including the windings of motors, solenoids and transformers.
2. Description of the Prior Art
Numerous coated magnet wires for use in electric motors are known in the prior art. However, each of the prior art magnet wires has proven to be less than completely satisfactory for hermetic motor applications.
Typically, prior art magnet wires have received an outermost coating of a dry lubricant such as a paraffin wax melting in the range of about 40.degree. to 60.degree. C. The wax is used to reduce friction on the wire, thereby to enhance windability and insertability. However, when a wax-coated magnet wire is used in a hermetic unit, the paraffin wax must be rinsed off with a solvent. Suitable solvents are hot aliphatic liquids, such as heptane, and aromatic liquids, such as toluene. These solvents remove the wax in order to avoid blockage of capillary orifices in the hermetic unit by any traces of wax remaining on the wire after assembly.
It is a principal object of the present invention to provide a magnet wire for hermetic motors which avoids any need for solvent removal of a lubricant from the wire after winding onto a coil.
It is a related object of the invention to provide a lubricant for magnet wire having properties consistent with normal operation of hermetic motors even under extreme temperature conditions.
Additional objects and advantages of the present invention will be apparent to persons skilled in the art from the following specification.